1. Field of the Invention
A following description relates to a boundary information providing apparatus, and more particularly, to a boundary information providing apparatus that transmits, to a receiver, information on a time point at which a two-dimensional (2D) video is switched into a three-dimensional (3D) video or the 3D video is switched into the 2D video in a 3D program including both the 2D video and the 3D video, thereby enabling the receiver to perform switching between the 2D video and the 3D video at a proper time.
2. Description of the Related Art
A binocular three-dimensional (3D) broadcasting system transmits streams with respect to a left eye image and a right eye image, simultaneously, to a receiver to provide a 3D broadcasting service. The receiver receiving the streams of the left eye image and the right eye image may provide a stereoscopic image to a viewer through 3D rendering. In case of the 3D broadcasting, the receiver may provide the 3D broadcasting only during a particular time period. Here, the receiver needs to properly perform switching between 2D and 3D corresponding to whether a currently provided program is 2D broadcasting or 3D broadcasting.
A conventional 3D broadcasting system uses a signaling channel of a transport level, such as program map table (PMT), virtual channel table (VCT), and service information (SI), to provide information on a currently provided broadcasting program type, for example 2D or 3D. Here, the 3D broadcasting system may insert type information in a descriptor using the signaling channel, and transmit the descriptor including the type information to the receiver. The foregoing method is generally used for transmission of program information since the signaling is easy to define and other program information may also be transmitted.
However, since the descriptor is transmitted at time periods to the receiver, it is difficult to transmit boundary information of an accurate level. A frame header may be used to solve the inaccuracy. According to a method using the frame header, the type information, that is, 2D or 3D, of a corresponding frame is inserted in the frame header of a video level and therefore boundary information may be transmitted in an accurate frame unit.
However, since the signaling channel such as PMT, VCT, and SI is mainly used as to information on a program being broadcasted, information on whether the currently provided program is a 3D type is provided also in the descriptor form through the signaling descriptor. On the other hand, information on the video frame header may be selectively used. To use the video frame header, two information should not conflict at a boundary between a 2D program and a 3D program.
Especially, when two broadcasting networks capable of providing different 2D services are used to transmit the left image and the right image of the 3D broadcasting, the receiver need to be prevented from synthesizing of a 3D video from two totally different 2D videos.